Over the course of the last 5 years I’ve learned a lot about my cacti through trial and error. A lot of what I learned has to do with how to water my cacti properly so that I can prevent root rot, but I have also learned that there are other environmental ailments my cacti face. Specifically my plants have suffered from etiolation, sun burn, over watering, and, most recently, a thrip invasion. I’ll talk through how I identified these problems and provide solutions on how to fix them.
A cactus or succulent develops etiolated growth when the plant doesn’t get enough light to properly grow. Instead of growing outward, an etiolated plant will grow overly tall and skinny as it reaches for the sun. It will also become much more pale in color. I’ve had most of my plants since I was a junior in college and they have been moved many times into different places in different lights. Because of this, many of my plants have experienced etiolation.
The only fix for a light deprived plant is to move it to a place where is receives better, more direct light such as south facing window, which will leave the etiolated places, but the plant will then begin to grow properly. If you would prefer your cacti or succulent to have a more uniform shape, you can use cuttings to propagate the more symmetrical sections of your plant. To propagate your etiolated cactus, use a sterile, sharp knife to cut about 1 inch below the desired, symmetrical section. Let the cutting scar for a few days before placing the cutting into soil. Before placing the cutting into the soil, you can choose to coat the bottom of the cutting in rooting hormone. Though this step is not necessary, it could increase your chances of success, especially if you are new to propagation. Do not water your cutting for a week and then water sparingly each week. This same process can be used for propagating etiolated succulents.
If you would rather give your cacti or succulent more light, you can always transition your cacti and succulents to a better lit area or even to living outside. A word of caution: When transitioning your plant to an area where there is more light, whether it’s inside or outside, make sure to make the transition gradually. If a cactus or succulent is not used to receiving sun and then begins receiving full sun, it can lead to sunburn.
In my current apartment, there are only 2 places that receive strong light: my bedroom and my patio, which are both south facing. As I’ve adapted to the space and as I’ve become more comfortable with my plants, I’ve been able to recognize when my plants need more or less light. Part of my routine each Sunday is to sun all my plants in the morning and rotate them so they get optimal light throughout the week. I do this because many of my previous living situations didn’t have the best light for my plants and a number of them etiolated. After rotating my plants a few times I noticed that once I began giving them better light, their skin began to change. Specifically, many of my cacti and succulents developed a uniform rust color on the side facing the sun. This kind of discoloration is characteristic of sunburn. According to Cacti Guide and Phelan Gardens, sunburn occurs in cacti and succulents that
- have low light needs and have been placed in direct sunlight;
- are in direct sun and suffer through long periods of dehydration; or
- are etiolated and have been living in low light for long periods of time.
I’ve had several plants that have had sunburn which include my Euphorbia ingens,Kalanchoe blossfeldiana, and Mammillaria longimamma. I’ve had my Euphorbia ingens planted in a container with sun loving mammillaria cacti that receives direct sunlight. I’ve since learned the hard way that this thorned, leafed South African succulent absolutely does not need direct sun. Not only did its skin burn, but the plant stopped producing it’s characteristic leaves that it uses to block the sun. I’ve since moved it to a shadier side of the table, but in order for it properly recover, I’ll need to repot it with more light sensitive plants. Both my Kalanchoe blossfeldiana and Mammillaria longimamma lived in low light conditions for a good amount of time and were subsequently burned when placed in direct light. The kalanchoe burned more badly as it was placed outside in direct sunlight with no transition.
There’s no way to reverse sunburn in cacti and succulents unless you catch it at the early stages. You can tell when a cactus or succulent is beginning to burn when the plant’s skin has a white discoloration. If you catch the burn at this stage, move your plant to a more shaded area and the plant’s skin will eventually heal itself. Otherwise, once a cactus or succulent is burned to the point where its skin is brown, the damage is permanent and your plant will need to grow out of it.
There are many things over watering can do to your cactus that includes split tissue and rot. Figuring out a good watering schedule for your plants can be challenging at times and in the beginning can go really right or really wrong. When I first started my cacti and succulent collection I more often than not made the mistake of over watering my plants. Because cacti and succulents often live in places that have limited water and nutrient supplies, they have adapted systems that make them excellent at retaining water. When you give a cactus or succulent too much water it will cause the tissue to swell and split. With good drainage and by purposefully instituting a drought, cacti and succulents can recover from over watering and the scarring will eventually heal. Unfortunately, if the cactus does not have good drainage and is left in humid conditions, then over watering can lead to a larger more systemic issue of rot. My Ferocactus glaucescens was one of the first cacti I ever collected. It was situated in pot without a drainage hole and had gravel glued around it. Of course, I over watered it, which caused the tissues to crack, but the combination of poor drainage and gravel caused the air around the cactus to become too humid and the base of the cactus began to rot. You can read more about how I saved it and my other over watered, rotting cacti here. So, my Ferocactus glaucescens not only has scars from splitting, but also scars from the rot.
Until last month, I had never experienced a bug problem with my indoor plants. The first and, so far, only plant to be infested has been my Gymnocalycium baldianium. If you saw my #plantbabyspotlight from awhile back, you’ll understand my disappointment when I realized I had a bug problem. During one of my Sunday rearrangements, I noticed that my cactus had brown spots all over it that almost looked like a rash or the damage done by spider mites or aphids. Upon closer inspection I noticed small, ovular bugs walking around in the crevices of my cactus, which as it turns out are thrips nymphs. These nymphs feed on plant sap in the same way as spider mites and aphids. They can also be killed in the same way using insecticidal soap. For the last month I have kept this cactus outside and have been treating it with my homemade insecticidal soap. You can read about its ingredients here. I use a q-tip soaked in my insecticidal soap to scrub the crevices of the plant as well as around the spines once per week. I’ve noticed a sharp decline in the number of thrips, and hope to bring the plant inside before the end of July. Despite this thrips invasion, my Gymnocalycium baldianium has persevered and has 2 new buds! Unfortunately, the thrips scars will remain, but will become less noticeable with time as the plant continues to grow.
Do you have questions about these cactus and succulent ailments? Do you have questions on how I treated my plants? Have any tips or tricks you’d like to share? Or do you just have questions about your indoor and outdoor plant babies? If you’d like to know more about how to heal your plant babies or if you have questions about your plant colony, leave a comment below or feel free to contact The Garden Generalist. I would love to hear from you!
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15 thoughts on “House Plants: How to Treat Common Cactus & Succulent Ailments”
This post has been extremely helpful.
I have several cacti that I grew from seeds a few years back and the taller ones split a little. Now I know why.
I recently grew some cacti from seeds and I’m pretty sure they are sunburned. I think I’ll switch their location
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So happy I could help you, Trish! If you have any questions feel free to shoot me an email at firstname.lastname@example.org. Wishing you and your plant babies well!
I have a xmas cactus that we put in the sun outside and the ends are turning purple what could cause this. Otherwise it is growing very big.
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Hi Sue! When a Christmas Cactus or any cactus really starts to turn purple/red it means that it’s getting too much sun. It’s basically cactus sunburn. I’d suggest moving it to a spot with indirect light or that gets more shade during the day.
My succulent looks like she is dying from the bottom up, the person who gave it to me potted it in an old candle jar and her leaves become mushy and yellow-ish… It looks like it may have some rot on the top where the leaves are still fleshy. I think maybe we overwatered it, How can I save her? we are really hoping to make it better and I think you are our only hope!
Hi, Amber! Sounds like your succulent got a little too much water. Is the stem still healthy? Like is it still sturdy or are there places where it is mushy and yellow, too? If the stem is still healthy, I would recommend potting it in new soil and not watering it for a month or so. New succulents will begin to form on the old stem after about a month or month and half. Depending on the succulent you have, you could potentially propagate new succulents from the healthy leaves. Take a look at my post about propagation for more info: https://thegardengeneralist.com/2016/06/22/how-to-propagate/
If you have any additional questions, feel free to email me here: email@example.com.
Hallo, I don’t know which of these ailments my cactus have, is there any way to help him out?? Here’s a picture: https://twitter.com/_fallen_one_/status/1008067275906314241/photo/1
Hi, Ivona! Based on your picture, I think your succulent is sunburned and a bit thirsty. Where does your plant usually live?
I have two a barbed wire/triangle cactus planted together in a large pot. First question, I cut the top of the two cacti because they were too tall. I think my mom used to cut this same cacti and it would continue to grow up normally from where she cit it. The only indication that she had cut it was an indentation at the cut line. I cut them and the only thing growing from the top are little baby cactus spears. Is this normal, did I cut it wrong, or is there something wrong with the cactus? Second question, at the base of one cactus and beginning on the cactus next to it, the skin looks dried out with a white powdery coating and what looks to be white mold growing at the base. From what I’ve read, this looks like it may be rot or is it the browning that happens when a cactus gets old or is it a combination of both. I hope you can help me. My mother gave me these and she has since passed away and has sentimental value to me. Thank you! Kirsten C
Hi Kirsten, would you mind sending over a few photos of your cacti to firstname.lastname@example.org? It will help me to better understand what may be going on with your cacti.
Thank you so much for this article!
I was trying to find the issue with Gymnocalycium baldianum plant for months with little luck – and in your article – I found all the answers. I live in Alexandria, VA, with windows facing northwest. Last summer, I started to notice the Orange covering on the succulent. As I was inexperienced with orange/rust coloration, I stumbled on an article that advised me to remove it. I wish I never saw that article, 😦
It led to more scarring; thankfully, the plant looks resilient, willing to live but the top about 80% covered in scars (burn and damage caused by me). At this point, with all the scars, it’s hard to see possible pests (if I have any).
Hi Kira! I’m glad that my article helped and I’m sorry your plant was scarred! Hopefully you won’t have any further issues with mold or pests!